This pin belongs to a collection created to commemorate atomic sites and honor the men and women who worked at each location. This pin is a tribute to the history of Hanford Site’s B-Reactor, the world’s first full-scale plutonium production reactor. The plutonium from the B-Reactor was used in the Trinity Test, as well as the atomic bomb “Fat Man”. The B-Reactor National Historic Landmark has been part of the Hanford Unit of the Manhattan Project Historical Park since 2008.